The ability to monitor the motion of a person's head has importance in many applications. For example, in many sports, the relative position and/or motion of a player's head is essential in executing a desired athletic movement. Typically, in order to achieve the correct head position or movement, the player must practice. Traditionally, such practice has encompassed repeating the position or movement until it is properly executed. A significant problem with this repetitive practice approach is the player must generally rely on self-inspection to determine whether the motion or position is correct. Endless hours of unknowingly practicing the incorrect motion will input improper data into the player's muscle memory and will make it difficult for the player to achieve the intended improvement. A second party observer (e.g., a coach) can sometimes provide insight to correct the motion. However, this method depends upon the knowledge, communication skills and availability of such an expert observer. A video tape recorder can substitute for an observer. However, using a video recording requires the purchase of costly equipment and often the tape can only be viewed after the practice session has taken place. Thus, corrections can only be attempted at a subsequent practice session.
Monitoring head movement and relative position has numerous safety applications. For example, in those sports considered to be contact sports (e.g., football, hockey, lacrosse, etc.), a player making contact with his or her head in the wrong position risks injury. A warning signal would give the player an opportunity to alter his or her head position in time to avoid injury. Current head gear for these types of contact sports do not provide any sensor information to indicate a dangerous head position.
A head position monitor has safety applications in situations where head position indicates other dangerous conditions. For example, certain movements of an automobile driver's head indicate that the driver has fallen asleep at the wheel or is not looking at the road. Many accidents could be avoided if the driver is prompted to regain proper head position. Likewise, in aviation a pilot's head position in certain instances can create a potentially dangerous situation. For example, when an aircraft is in a turn and a pilot's head is positioned at an improper angle with respect to the vertical of the centerline of the aircraft, disorientation can occur. This may occur when the inner ear of a pilot provides an erroneous sense of turn information to the pilot while making a prolonged, constant bank turn such that the pilot may incorrectly believe that he or she has ceased turning and has leveled off. While many cockpits include attitude and altitude indicators to alert the pilot to the aircraft's attitude and altitude, current head gear for pilots do not provide a head position sensor indicating a dangerous, prolonged, constant banked turn. Providing an alarm alerting the pilot of improper head position can be a significant safety advantage in this circumstance.
Many drawbacks exist among current head position monitors. For example, many devices are not sensitive to small amplitude head motions, thus, these motions remain undetected. Another drawback of existing devices is that often the desired motion requires a deliberate, predetermined head motion and many existing devices are set to merely indicate when the head has moved. For example, to properly hit a baseball the batter's head should move to follow the pitch from the pitcher to the catcher. Existing head motion sensors that merely indicate when a batter's head moves are not useful to indicate the proper head motion to the batter. Another drawback is that many existing devices are bulky and cumbersome. To be practical, a head motion monitor should interfere with the wearer and activity as little as possible. Another drawback is that many existing devices are not adaptable to the skill level of the wearer. For example, the acceptable range of head motion for a professional baseball batter is smaller than the acceptable range of head motion for a little league baseball batter and many existing devices cannot adapt to these different ranges.
These and other drawbacks exist in current devices.